/Engine/Source/Runtime/Engine/Classes/PhysicsEngine/ConstraintInstance.h
Pass in reference orientation in (maintains reference position). If the constraint is currently active, this will set its active local pose. Otherwise the change will take affect in InitConstraint.
void SetRefOrientation ( [EConstraintFrame::Type](API\Runtime\PhysicsCore\Chaos\EConstraintFrame__Type) Frame, const FVector & PriAxis, const FVector & SecAxis )